Small light lamps such as light emitting diodes (LEDs) have been widely used as indicators or components of displays because of their high mechanical stability, low operating voltage, and long service life. When a plurality of the small light lamps are arranged in a two dimensional array and inserted into an electrically wired board configured to control each lamp, the resulting structure forms a large display board. In one prior system, such large display boards have been employed as score boards in sports arenas.
Manufacturing of display boards requires wiring of internal electrical circuit for controlling each lamp and wiring sockets for receiving each lamp. The laps also must be individually inserted into the sockets. The preceding requirements, among others, make the manufacturing of display boards to be cumbersome and not readily adaptable to an automated assembly line processing. In turn, the display boards are ordinarily custom designed with high manufacturing costs.